I too had issues exporting an FCP7 project to PR CC through XML. At a certain point began to see wildly anomalous and random clips in the imported sequence . . . black, barred, duplicate shots.
This sequence was about 40 minutes long with mostly straight cuts.
The workaround I found was to break the sequence into two parts and import the second half as a separate xml, they marry them in PP CC.
Like many things with PP CC, this may take some experimentation, but try exporting shorter segments.
Best,
Robert
Robert Withers
Independent/personal/avant-garde cinema, New York City